<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script> 
    function getRandomColor(flag){
      let arr = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f']
      let str = '#'
      if (flag) {
        for (let i = 0; i< 6 ; i++){
          let ran = Math.floor(Math.random()*arr.lenght)

          str += arr[ran]
        }
        return str
      }else {
        let r = Math.floor(Math.random()*256)
        let g = Math.floor(Math.random()*256)
        let b = Math.floor(Math.random()*256)
        return`rgb(${r},${g},${b})`
      }
    }
    console.log(getRandomColor(true))
    console.log(getRandomColor(false))
    // const div = document.querySelector('div')
    // divv.st
  </script>
</body>
</html>